Flexible-hinge leaf.



J. BARKER.

FLEXIBLE HINGE LEAF.

APPLICATION FILED JULY15,1911.

1 1 03 9 1 1 Patented July 14,1914,

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JAMES BARKER, 015 DETROIT, MICHIGAN.

FLEXIBLE-HINGE LEAF.

Specification of Letters Patent.

Patented July 14:, 1914:.

Application filed July 15, 1911. Serial No. 638,741.

To all whom it may concern Be it known that I, JAMES BARKER, a citizenof the United States of America, residing at Detroit, in the countyofWayne and State of Michigan, have invented certain new and usefulImprovements in Flexible-Hinge Leaves, of which the following is aspecification, reference being had therein to the accompanying drawings.

The invention relates to leaves more particularly designed for use inconnection with loose-leaf lodgers, and the invention consists in thepeculiar construction of the hinge section for the leaf as hereinafterset forth.

In the drawings,Figure 1 is a perspective view of the leaf; Fig. 2 is anenlarged diagrammatic sectional view illustrating the hinge section.

In the present state of the art, leaves for lodgers have beenconstructed in whicha flexible hinge section is formed by thinning aportion of the paper stock, thereby increasing the flexibility.

The present invention relates to a construction in which flexibility isobtained without any thinning or reduction in the paper stock, but whichat the flexing point is of a softer nature. Such a construction ispreferably obtained by treating the material with a softening compoundwhich renders'it less resilient and more flexible.

In the specific process which is preferably employed for forming thehinge section, the paper stock is treated with a softening solution forwhich the following formula is suitable:

Wood alcohol 5t07 ounces. Oxalic acid lounce. Glycerin 5- ounce. I

The solution may be applied by any suitable implement such as a'brushbeing applied to the surface of the leaf and confined to the area of thesection which is to be rendered flexible. After the solution haspenetrated the fibers the surplus material is wiped off and the sheetdried. The result of the treatment is that the section to which theliquid is applied is rendered flexible and forms a suitable hinge.

In the drawings, A represents a leaf such as a loose-leaf ledger leaf,and the shaded strip indicated at B represents the section whlch hasbeen treated.- In Fig. 2 this is dlagrammatically illustrated byrepresenting the section B of a different texture than that of the bodyof the leaf.

While I have described a specific compound for use in my process it isobvious that there may be many equivalents for producing the sameeffect. The particular process for obtaining the product does not formany portion of the present invention but will be the subject matter of adistinct application for patent.

What I claim as my invention is:

1. A book leaf formed of paper having a I hinge portion, comprising anarrow section integral with the body of the leaf impregvnated with asoftening material, increasing the flexibility of the hinge portion overthat of the body of the leaf.

2. A book lea-f formed of paper having a hinge portion, comprising anarrow section integral with the body of the leaf of uniform thicknesswith the body, said section being impregnated with a softening-material,increasing the flexibility thereof over that of the body of the leaf.

3. A boolrleaf formed of paper of uniform stock throughout and having anarrow section integral with the body of the lea-f, treated with asoftening material increasing the flexibility of said section over thatof the body of the leaf.

In testimony whereof I ailix my signature in presence of two witnesses.

JAMES BARKER.

Witnesses:

W. J. BELKNAP, ADELAIDE I. ADAMS.

Copies of thll patent may be obtained for in cents each, by addressingthe Gommiuloncr ot l'atentl, Washington, D. 0.

